旋光效应对Bi12SiO20晶体中光动量及角动量的影响  

Influence of Optical Activity on Optical Momentum and Angular Momentum in Bi12SiO20 Crystals

作　　者：陈舒婷 郭昊旭 邱晓东 陈理想 Chen Shuting;Guo Haoxu;Qiu Xiaodong;Chen Lixiang(College of Physical Science and Technology,Xiamen University,Xiamen ,Fujian 361005,China)

机构地区：[1]厦门大学物理科学与技术学院

出　　处：《激光与光电子学进展》2019年第13期220-226,共7页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(11474238,91636109);教育部新世纪优秀人才支持计划(NCET-13-0495);福建省杰出青年基金(2015J06002)

摘　　要：从Maxwell方程组出发,将与旋光效应相关的二阶非线性电极化作为线性电极化的微扰项,并结合角谱表示理论,以傍轴高斯光束作为入射光场,研究了光束在具有自然旋光性的Bi12SiO20晶体中的传播问题,并分别采用Minkowski和Abraham两种形式的光动量,得出Bi12SiO20晶体中的光动量及角动量表达式。结果表明,旋光性的存在使得晶体中的Minkowski动量和Abraham动量的比值不再是晶体折射率的平方。采用Minkowski角动量密度形式,可以发现,光场与晶体之间的角动量会发生耦合,虽然光场自身的角动量不守恒,但光场和晶体的总角动量守恒。Beginning from Maxwell′s equations and by considering the second-order nonlinear polarization related to the optical activity as the perturbation of linear polarization,we investigate the propagation behavior of the paraxial Gaussian light which acts as incident light in the optically active medium Bi12 SiO20 and utilize the Minkowski and Abraham momenta to obtain the expressions of optical momentum and angular momentum in Bi12 SiO20 crystals.Further,we obtain that the ratio of Minkowski momentum to Abraham momentum is not equal to the square of the refractive index of the crystal because of the existence of optical activity.In the Minkowski picture,because of the coupling of the angular momentum between the light and the crystal,the angular momentum of the light field is not conserved,whereas the total angular momentum of the light and crystal is conserved.

关 键 词：物理光学 晶体光学 旋光效应 光动量 角动量 

分 类 号：O437.1[机械工程—光学工程]